Analysis Of Mixing Technique Based On Microfluidic Chip

The researches about mixing characters, difficulties in mixing and methods to enhance mixing in microscale in recent years were introduced. Based on the previous investigation, a method of fabricating simple and efficient micromixers was presented. In the designing process, simulations and experiments were applied. The mixing performance of micomixer designed was simulated first by FLUENT, and then glass-PDMS microchip was fabricated to examine and verify the simulation results. Finally, a simple and efficient micromixer was designed and fabricated based on simulation and experiment results.(1) The structure parameters of the microchip designed, including inlet angle, width of inlet channel and structure of mixing unit, were simulated by FLUENT to characterize their influence to mixing performance;(2) Glass-PDMS microchip was fabricated, and 10mmol/L methylene blue solution and deionized water were pumped into the microchip. The mixing condition was pictured by the microscope and the gray scale analysis of the pictures by MATLAB was introduced to qualitatively characterize the mixing performance;(3) By comparing the simulation and experiment results, the causes resulting in deviation were analyzed and a simulation model was set up to guide the design of the miromixer;(4) 180°inlet angle,200μm channel width and 69°baffle mixing unit were chosen to constitute the micromixer. The period of the mixing unit was introduced to enhance the mixing performance. A 28-period micromixer was fabricated to achieve about 80% mixing uniformity.